The explosive adoption of video-enabled wireless mobile devices has caused an explosion of data traffic and exposed the capacity constraints of conventional wireless network topology.
Conventional wireless network (e.g., cellular network) deployment requires careful planning to maximize frequency reuse, minimize coverage dead zones and minimize inter-cell interference, etc. The deployment is labor intensive due to significant amount of measurements and field trials. To reduce the cost of deployment, many network operators deploy macro cells which provide larger coverage footprint and higher capacity. This approach works when the subscribers' service types are mainly conversational (e.g., voice), interactive (e.g., web browsing, instant messaging, etc.), or low rate streaming. These are the typical service types for 2G (e.g., GSM) and early 3G (e.g., UMTS and CDMA2000/EV-DO) cellular networks in which a macro cell provides adequate quality of service to fulfill a majority of subscribers' needs.